If the magnetic flux is uniform as is assumed in our numerical example,
the current is distributed
as shown in Fig. REF  (b)
and the dashed curve in the left panel of
Fig. REF .
The current does not penetrate outside the polar magnetic flux;
if it did,
the electromagnetic force would be in opposite
direction to the braking force, and as a result,
the elastic energy would be increased.
It must be noted here that the inertial force dominates in the equatorial region.
Therefore,
if the polar cap magnetic flux is bent towards the equator such as
shown in the right panel of Fig. REF ,
then the current penetrate to the equatorial region,
and the braking stress is much more relaxed.
We find that the distribution of the braking torque
depends thoroughly on the
distribution of the polar cap magnetic flux inside the star.
The Hall effect by the magnetospheric current, in other words,
the drift current due to the braking force, has little effect
to the background magnetic field inside the star.
Therefore, the key factor for the distribution of the braking force is
the background magnetic field structure, for which the magneto-thermal evolution
has been intensively investigated
(see e.g., [1]}).
